Sample Graphics

Graphics Gallery

This gallery is to show the designs can be created from Lazarus and drawing tools, like BGRABitmap.

gdgfx

Name: gdgfx 'Gradient Graphics'

Author: Lainz

Description: Shows how to create buttons and gradients with and without transparency in Lazarus using BGRABitmap and an enhanced version of Double Gradient that supports alpha.

Notes: Tested on Win32. Download Includes used version of BGRABitmap & DoubleGradient.

Picture:

Top-Left: 'like flash player setup button' / Top-Right: 'like win7 explorer toolbar' / Bottom: double gradient with alpha / Background: same as bottom.

Download: gdgfx.7z (60.01 KB)

Flash Player Button

Add a new TPaintBox, set 'btn1' as name. Go OnPaint event and add this code:

<delphi>var

 tempbmp1, tempbmp2: TBGRABitmap;

begin

 // Background Gradient
 tempbmp1:=TBGRABitmap.Create(btn1.Width,btn1.Height,BGRA(104,104,104,255));
 tempbmp1.Canvas.GradientFill(Rect(1,Round(btn1.Height*0.25),btn1.Width-1,btn1.Height-1),$686868,$404040,gdVertical);

 // Frame Border
 tempbmp1.Canvas.Brush.Color:=$181818;
 tempbmp1.Canvas.FrameRect(btn1.ClientRect);

 // Light Gradient
 tempbmp2:=TBGRABitmap.Create(btn1.Width,btn1.Height,BGRA(0,0,0,0));
 tempbmp2.GradientFill(1,1,btn1.Width-1,btn1.Height-1,
 BGRA(255,255,255,34),
 BGRA(255,255,255,10), gtLinear,
 PointF(btn1.ClientRect.Right,btn1.ClientRect.Top),
 PointF(btn1.ClientRect.Right,btn1.ClientRect.Bottom),
 dmDrawWithTransparency,True,False);
 tempbmp2.AlphaFillRect(2,2,btn1.Width-2,btn1.Height-2,0);

 // Merge Bitmaps
 tempbmp1.Canvas.Draw(0,0,tempbmp2.Bitmap);

 // Paint in Canvas
 btn1.Canvas.Draw(0,0,tempbmp1.Bitmap);

 // Free Bitmaps
 tempbmp1.Free;
 tempbmp2.Free;

end;</delphi>

Windows 7 Explorer Toolbar

Add a new TPaintBox, set 'btn2' as name. Go OnPaint event and add this code:

<delphi>var

 backBmp, lightBmp: TBGRABitmap;
 gradBmp: TBitmap;

begin

 // Background Gradient
 gradBmp := DoubleGradientFill(
             btn2.ClientRect,
             $FFFAF5,$FAF0E6,
             $F4E6DC,$F7E9DD,
             gdVertical,gdVertical,gdVertical,0.5);

 // Use as background
 backBmp := TBGRABitmap.Create(gradBmp);
 gradBmp.Free;

 // Light Gradient
 lightBmp:= TBGRABitmap.Create(btn2.Width,btn2.Height,BGRA(0,0,0,0));
 lightBmp.Rectangle(0,0,btn2.Width,btn2.Height-2,
    BGRA(255,255,255,100),
    dmSet);
 lightBmp.SetHorizLine(0,btn2.Height-1,btn2.Width-1,BGRA(160,175,195,255));
 lightBmp.SetHorizLine(0,btn2.Height-2,btn2.Width-1,BGRA(205,218,234,255));

 // Merge Bitmaps
 backBmp.PutImage(0,0,lightBmp,dmDrawWithTransparency);
 lightBmp.Free;

 // Paint in Canvas
 backBmp.Draw(btn2.Canvas,0,0,True);
 backBmp.Free;

end;</delphi>

Double Gradient with Alpha

Add a new TPaintBox, set 'btn3' as name. Go OnPaint event and add this code:

<delphi>var

 myBitmap: TBGRABitmap;

begin

 myBitmap:= DoubleGradientAlphaFill(
 btn3.ClientRect,
 BGRA(0,0,0,100),BGRA(255,255,255,100),
 BGRA(100,100,100,100),BGRA(150,150,150,100),
 gdVertical,gdVertical,gdVertical,0.5);
 btn3.Canvas.Draw(0,0,myBitmap.Bitmap);
 myBitmap.Free;

end;</delphi>

As you can read you need both DoubleGradient & DoubleGradientAlphaFill:

<delphi>unit doublegradient;

{$mode objfpc}{$H+}

interface

uses

 Classes, Graphics,
 BGRABitmap, BGRABitmapTypes;

function DoubleGradientAlphaFill(ARect: TRect; AStart1,AStop1,AStart2,AStop2: TBGRAPixel;

 ADirection1,ADirection2,APos: TGradientDirection; AValue: Single): TBGRABitmap;

function DoubleGradientFill(ARect: TRect; AStart1,AStop1,AStart2,AStop2: TColor;

 ADirection1,ADirection2,APos: TGradientDirection; AValue: Single): TBitmap;

implementation

function DoubleGradientAlphaFill(ARect: TRect; AStart1,AStop1,AStart2,AStop2: TBGRAPixel;

 ADirection1,ADirection2,APos: TGradientDirection; AValue: Single): TBGRABitmap;

var

 ABitmap: TBGRABitmap; ARect1,ARect2: TRect; APoint1,APoint2,APoint3,APoint4: TPointF;

begin

 ABitmap := TBGRABitmap.Create(ARect.Right,ARect.Bottom);
 if AValue <> 0 then ARect1:=ARect;
 if AValue <> 1 then ARect2:=ARect;
 if APos = gdVertical then begin
   ARect1.Bottom:=Round(ARect1.Bottom * AValue);
   ARect2.Top:=ARect1.Bottom;
 end
 else if APos = gdHorizontal then begin
   ARect1.Right:=Round(ARect1.Right * AValue);
   ARect2.Left:=ARect1.Right;
 end;
 if ADirection1 = gdVertical then begin
   APoint1:=PointF(ARect1.Left,ARect1.Top);
   APoint2:=PointF(ARect1.Left,ARect1.Bottom);
 end
 else if ADirection1 = gdHorizontal then begin
   APoint1:=PointF(ARect1.Left,ARect1.Top);
   APoint2:=PointF(ARect1.Right,ARect1.Top);
 end;
 if ADirection2 = gdVertical then begin
   APoint3:=PointF(ARect2.Left,ARect2.Top);
   APoint4:=PointF(ARect2.Left,ARect2.Bottom);
 end
 else if ADirection2 = gdHorizontal then begin
   APoint3:=PointF(ARect2.Left,ARect2.Top);
   APoint4:=PointF(ARect2.Right,ARect2.Top);
 end;
 if AValue <> 0 then
 ABitmap.GradientFill(ARect1.Left,ARect1.Top,ARect1.Right,ARect1.Bottom,
 AStart1,AStop1,gtLinear,APoint1,APoint2,dmDrawWithTransparency,True,False);
 if AValue <> 1 then
 ABitmap.GradientFill( ARect2.Left,ARect2.Top,ARect2.Right,ARect2.Bottom,
 AStart2,AStop2,gtLinear,APoint3,APoint4,dmDrawWithTransparency,True,False);
 Result:=ABitmap;

end;

function DoubleGradientFill(ARect: TRect; AStart1,AStop1,AStart2,AStop2: TColor;

 ADirection1,ADirection2,APos: TGradientDirection; AValue: Single): TBitmap;

var

 ABitmap: TBitmap; ARect1,ARect2: TRect;

begin

 ABitmap := TBitmap.Create;
 ABitmap.Width:=ARect.Right;
 ABitmap.Height:=ARect.Bottom;
 if AValue <> 0 then ARect1:=ARect;
 if AValue <> 1 then ARect2:=ARect;
 if APos = gdVertical then begin
   ARect1.Bottom:=Round(ARect1.Bottom * AValue);
   ARect2.Top:=ARect1.Bottom;
 end
 else if APos = gdHorizontal then begin
   ARect1.Right:=Round(ARect1.Right * AValue);
   ARect2.Left:=ARect1.Right;
 end;
 if AValue <> 0 then ABitmap.Canvas.GradientFill(ARect1,AStart1,AStop1,ADirection1);
 if AValue <> 1 then ABitmap.Canvas.GradientFill(ARect2,AStart2,AStop2,ADirection2);
 Result:=ABitmap;

end;

end.</delphi>